Plasticized compositions



Patented Aug. 7, 1945 rmsri'crzsn coMrosrrroNs Robert H. Barth, Ridgewood, and Harry Burrell,

" Paramus, N.

J., assignors, by mesne assignments, to Heyden Chemical Corporation, New Xork, N. a corporation of Delaware No Drawing. Application July 22, 1942,

" Serial No. 451,946

1 Claim. (01. 106-180) This application is a continuation-in-part of our:prior and copending application Serial No.

378,052, filed'February 8, 1941, which has issued as Patent No. 2,356,745. This invention-relates to the use of esters of morethan one acid radical oi, pentaerythritol and related compounds as plasticizers for a wide variety of resins and cellulose derivatives with V which they are compatible, and in which they serve to plasticize, soften, elasticize, lubricate, and otherwise modify these compounds. The resulting compositions maybe molded under pressure, dissolved in solvents to form coating compositions,

extruded to form ribbons, nbers, o'r structural shapes, emulsified, or otherwise prepared to be used as textileassistants, and so 'forth.

'Ihe esters employed incarrying out-this invention may be used with cellulose nitrate, cellulose acetate, cellulose acetobutyrate and other celluloseesters, ethyl cellulose, methyl cellulose, benzyl polystyrene, polyvinyl esters and acetals, chlorirubber, phenol-formaldehyde, urea-tormaldehye, melamine-formaldehyde and other synthetieresins, castor oiLtriacetin, tricresyl phos-:

phate, dibutyl phthalate and other plasticizersit necessarsnand wither-without such solvents, pigments or fillers as maybe desirable. 'I'he plasticizers may be incorporated with these ingredients according t methodswell known in i the art, as for example by dissolving in amutual invention. Because these materials are solids,

because they are water sensitive, and for other reasons, their use-has been limited. We have fou'nd, however, that certain other esters and classes of esters are highly desirable as modifying cellulose and "othercelluloseethers, damar, ma-

nila, rosin, ester gum, and other natural resins,

amounts of related hydroxylatedsubstances are also obtained. One of. these, which is obtained in a considerable amount, is dipentaerythritol,

' which is an ether having the following'structure:

cmon CHiOE nomoiz-cm-o-cm- CHzOH r5011 HZOH (See Briin, Ueber den Dipentaerythrit, Wilhelm Graven, Krefeld, 1930). Another related hydroxylated substance, obtained in somewhat smaller amounts, is white and crystalline, melts at 230-- 240" 0., and has a hydroxyl content of 33%. It is related to dipentaerythritol in that it contains pentaerythritol residues bound by ether linkages. Regardless of chemical structure, for purposes of definition in this specification and in the claims, this substance will be termed pleopentaerythritol.

According to the best evidence available, pleopentaerythritol is probably .a mixture of dipentaerythritol, tripentaerythritol, and possibly additional related alcohols.

Dipentaerythn'tol, tripentaerythritol, and pleopentaerythritol may be grouped together under the generic term polypentaerythritols, by which term is meant those compounds of higher molecular weight than pentaerythritol which are formed either actually or theoretically'by etherifying one .or more of the hydroxyl groups of pentaerythritol with other pentaerythritol residues.

The normal esters of pentaerythritol andthe polypentaerythritols may be {ormed by using erythritol and polypentaerythritols may be menagents, and these will be pointed out, and other objects of the invention will be indicated.

In the manufacture of Pentaerythritol by the condensation of acetaldehyde and formaldehyde, in addition to the pentaerythritol itselr, smaller tioned acetic, propionic, butyric, lauric and other straight or branched-chain fatty acids, isobutyric, valericgphenylacetic, 2-ethylhexoic, levulinic, and other carboxylic acids, including abi'etic.

Mixed esters such as pentaerythritol diacetate dipropionate, pentaerythritol diacetate dibutyrate, dipentaerythritol diacetate dipropionate dibutyrate, dipentaerythritol triacetate tripropi'onate, etc., are excellent plasticizers. They are Normal esters (that is, pentaerythrito -type esters in which substantially all of the acid radicals are identical) are also good plasticizers.

Pentaerythritol butyrate, for instance, combines several excellent properties of a liquid plasticizer. In general, however, the normal esters oi the polypentaerythritols are more adapted to plasticizer usage than the corresponding pentaerythritol esters, since they are usually lower melting. The acetate 01' pleopentaerythritol is especially indicated, since the hardness of compositions plasticized with this compound does not materially decrease with increasing proportions of the plasticizer.

The following examples are intended as illustrative only, and should not be so construed as to limit the invention as to scope or proportions. Parts are by weight.

Example 1.-A charge of pentaerythritol or its equivalent of a polypentaerythritol was refluxed with a mixture consisting of a suitable carboxyllc acid in an amount equal to 110 mol per cent at that required for complete esteriiication, toluene in an amount equivalent to one-half to Q one-third the pentaerythritol or polypentaerythrltol weight and concentrated sulfuric acid in an amount equivalent to one-quarter to onehalf per cent of the total weight of reactants, until the theoretical amount of water was removed and collected in a trap designed for that Table I is: P i ht o f onwe Parts by Compound weightol i g? weight aclduud Pound used Pentserythritol tetra- 416.3 180-190 It 1,940 tso butyrate. 2mm. Dipentaerythritol hexa- 674.3 1,440 636 butyrate. Dipentaerythritol hexa- 500.2 1,210 035 propionate. Pleopentserythritol pro- (0 980 000 pionated. Pleopentserythritol bu- 1,166 600 tyrated. Pentaerythritol tetra- 402 (m.p.) 2,079 680 chloroacetate.

Not known.

by distillation and the products either distilled under vacuum, or treated with decolorlzing charcoal or subjected to suitable recrystallization procedures. The following table lists the particular compounds made by this general method.

Table II Parts by Oalcu- Melt- Parts by i m isted weight 01 m mol. po l t, acetic z f weight 0. anhydride pound Dipcntaerythritol housesa Plteofientaerythrltol, acert mryihnwi totrabensoeto m1 70-15 on I Benioyl chloride used.

Example 3.-When a mixture of pentaerythritol and a pentaerythritol tetraester is heated in the presence of an alkaline catalyst. such as anhydrouspotassium carbonate, an alcoholysis of the ester occurs. Thus when one molecular equivalent oi pentaerythritol and one molecular equivalent oi pentaerythritol tetraacetate, m. p. 82, were heated with a small amount (e. g. 0.1%) 01 potassium carbonate at C. for two to four hours,

new products were formed which contained both hydroxyl and acetate groups. When this material was vacuum distilled at 2 mm. pentaerythritol diacetate, b. p. 207-215, was obtained as the major product. Similarly, ii. one mol of pentaerythritol and three mols oi the tetraacetate are heated with the catalyst and distilled at a pressure of- 2 mm. a new monohydroxy triacetate compound of pentaerythritol is formed, b. p. l'l6-.-l82 C. Similarly, there have been made hydroxy acetates of dipentaerythritol and hydroxy propionates of pentaerythritol. Some of these can be distilled while others are too high boiling. The monoacetate oi. pentaerythritol has not been distilled, although it has been made by this Example 4.-Mixed esters may be formed from the products of Example 3 by heating the hydroxy ester under reflux with an acid chloride or an-' hydride of an acid diflerent from that used to provide the ester groups in the hydroxy ester. Typical mixed esters prepared in this fashion are listed in the following table.

Table III Calcu- Starting lated Ph sicai Compound hydroxy y mol. :0 rties weight ester D De Pentaerythritol triace- 528 Pentaerythrltol M.p.30-38 C.

tate monostesrate. monostearstc. Pentaerythritol trl- 514 Pentaerythritol Soft wax.

proplonate monomonomyrimyristate. state. Pentaerythrltol trl- 318 Peutaerythritol B. p. 162-164 acetate monopropiotnscetate. at 2 mm. as e. Pentaerythl'itol di 332 Pentaerythritol B. p. l73-l80 acetate dipropionste. diacetate. at 2 mm. Dipentaerythntol trl- 548 Dipentserythri- Vlseousllquid.

acetatetri ropionate. to] triacetste. Peutaeryt ritol di- 360 Dipentaerythri- B. p. -165" acetate dibutyrate. tol diacetate. at 2 mm.

Example 5.--when one molecular equivalent of pentaerythritol-and 2 or more molecularequivalents each of the anhydrides of acetic and propionic acid were refluxed together, both acid groups entered the molecule in such a way that 90% of the product was pentaerythritol diacetate dipropionate, b. p. 1'73-180 at 2-3 mm.

Example 6.-Molding compositions were prethe compositions of lacquers which may be made up using the plasticizers of this invention.

7 acter, having a great "nerve or elasticity.

It may be seen from these examples that the pentaerythritol plasticizers have a widespread compatibility and. may be used in considerable amounts in lacquers.

Example 8-The following formulas illustrate 70 Formula 1 pared by mixing 150 parts oi a 83.3% solution of v 7 Parts cellulose acetate (equivalent to 50 parts on a dry 5 Chlorinated rubber 2 basis) with 5.5 parts of the pentaerythritol dempentaerythritol hexaproplonate '9 rivatives listed below'as plasticizers. The volatile Cumamn resin 1 solvent was allowed to evaporate and the hard, Xylene horny residue was comminuted. The resulting molding compositions were hot pressed at 175 C. Fm'muza 2 I at 2000 lbs. per sq. in. pressure. The die was Part5 chilled before-ejecting the piece. The molding Cellulose acetobutyrate. low viscosity 12 properties are shown in the following table. Dewaxed dammar Pleopentaerythritol propionate 3 Table IV 15 Acetone 48 Methyl Cellosolve acetate 13 Plasticizer Molding properties Molded piece Ethyl lactah: 3 I .Butanol 4 1 Pentaerythritol Soitened quicklyand Glass clear, well Ethylene dichloride 61 diacetate diproflowed easily and formed, glossy; T011101 54 pionste. well. an excellent In H 2 Dlpentaerythritol softened sll htly Molding oi identi- Formula 3 hexapropionate. slower than a ove cal a pearance Parts 7 gf fi gx gf my with Cellulose acetate (low viscosity lacquer '0 Pleopentaerythrito! Soltenedquicklyond Molding of identitype) Immune g 33$? Pentaerythritol diacetate dipropionate 10 Methyl ethyl ketone 37 Acetone '15 1 Example 7.-The following table records the Diacetone alcohol. 15 compatibility Of the listed 13187501012818 with a t The versatility and wide applicability f t variety of film iorming materials. The symbols mixed t r of entaerythitol andof polypens have the meanings: taerythritols is evidenced in the foregoing exem- C=compatible. ples. Many modifications or these esters are pos- 10.25, or 67=approximate maximum per cent of sible, and the various permutations and combinaplasticizer which can be used to provide a satistions of mixed esters may easily be arranged to factory film. fill a specific need by one skilled in the art, by I=incompatible. following the general and specific methods given. T=compatible, but film wastacky. Having thus described our invention, what we =3: 0% ts 0.. s 0 e5- 0 0 s 00s as Filmlormer 5.05 .53. E' g fl 32% 53% :22 35 5'5 ESE 35E EgEl 530 e5; 00% g 0 age .50. is 3E3 as; g a 55 7 '5 ME a? =3 a e1ssZsPas Oollulosenitntc 0.07 0.07 0.20 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07 oil 0.07 0.07 I 0.20 0.20 0.20 0.10 I 0.07 0.07 I

0.07 0,07 0.10 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.20 1 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.20 8.2; 0.07 0.07 0.07 0.07 0.07 0.07 T167 T167 1 T167 T167 0.20 0.10 0.20 0.10 0.10 1 0.20 0.07 I 0.20 V 0.07 0.10 1 I 0.20 0.01 r 0.07 I, I 0.20 0.20 0.20 0.20 0.10 0.10 I 0.20 1 .20 0.20 V 0.20 I Bakelite x11 0100"" 'l.25 T20 I Ester gum 0.10 T25 0.10 Cumsronrcsin u} 0.26 0.25 Rosi T20 2220 Sbells $322 0.20 0.20 Urea-butsnol-Iormsldehyde resin 0.67 I I 0.67 0.25 0.25 0.26 0.67 0.67

claim as new and desire to secure by Letters Patent is: I

A composition comprising a material selected from the group consisting of film-forming resins and cellulose esters and ethers and as a plasticizer for said material and incorporated therewith a mixture 01' pentaerythritol diacetate dipropionate and dipentaerythritol ,triacetate tripropicnate.

ROBERT H.- BAR'I'H. HARRY BURRELL. 

